Which of the following best describes a comet?
- A. A small planet orbiting the Sun between Mars and Jupiter.
- B. A chunk composed primarily of metal that enters Earth's atmosphere.
- C. A chunk composed primarily of rock, ice, and dust orbiting the Sun in an elliptical path.
- D. A dark region that appears periodically on the surface of the Sun.
Correct Answer & Rationale
Correct Answer: C
Option C accurately describes a comet as a chunk composed primarily of rock, ice, and dust that orbits the Sun in an elliptical path. This definition captures the essential components and behavior of comets. Option A incorrectly defines a comet as a small planet, which is misleading; comets are distinct from asteroids and do not have the same characteristics. Option B describes a meteoroid, which is a metallic chunk entering Earth's atmosphere, not a comet. Option D refers to sunspots, which are dark regions on the Sun's surface, unrelated to comets. Each incorrect option misrepresents the nature of comets, highlighting the unique characteristics of these celestial bodies.
Option C accurately describes a comet as a chunk composed primarily of rock, ice, and dust that orbits the Sun in an elliptical path. This definition captures the essential components and behavior of comets. Option A incorrectly defines a comet as a small planet, which is misleading; comets are distinct from asteroids and do not have the same characteristics. Option B describes a meteoroid, which is a metallic chunk entering Earth's atmosphere, not a comet. Option D refers to sunspots, which are dark regions on the Sun's surface, unrelated to comets. Each incorrect option misrepresents the nature of comets, highlighting the unique characteristics of these celestial bodies.
Other Related Questions
Which TWO of the following are true statements about hurricanes?
- A. They are typically over 160 kilometers, or 100 miles, in diameter.
- B. They form over cold water in Earth's polar regions and move slowly.
- C. They develop quickly and usually last for less than 30 minutes.
- D. They can have sustained wind speeds that are over 200 kilometers per hour.
Correct Answer & Rationale
Correct Answer: A, D
Hurricanes are vast systems, often exceeding 160 kilometers (100 miles) in diameter, making option A true. Additionally, they can reach sustained wind speeds over 200 kilometers per hour, confirming option D. In contrast, option B is incorrect as hurricanes form over warm waters, typically in tropical regions, not cold polar waters. Moreover, they do not move slowly; they can travel at significant speeds. Option C is also false; while hurricanes can develop rapidly, they generally last for several days, not just 30 minutes. Understanding these characteristics is crucial for recognizing the nature and impact of hurricanes.
Hurricanes are vast systems, often exceeding 160 kilometers (100 miles) in diameter, making option A true. Additionally, they can reach sustained wind speeds over 200 kilometers per hour, confirming option D. In contrast, option B is incorrect as hurricanes form over warm waters, typically in tropical regions, not cold polar waters. Moreover, they do not move slowly; they can travel at significant speeds. Option C is also false; while hurricanes can develop rapidly, they generally last for several days, not just 30 minutes. Understanding these characteristics is crucial for recognizing the nature and impact of hurricanes.
The rotation of Earth around its axis is responsible for which of the following?
- A. The force of gravity
- B. The day and night cycle
- C. The temperature differences between seasons
- D. The movement of continents relative to one another
Correct Answer & Rationale
Correct Answer: B
The rotation of Earth around its axis creates the day and night cycle, as different parts of the planet face the Sun and then move into its shadow. This explains why we experience daytime and nighttime in a 24-hour period. Option A is incorrect; gravity is primarily caused by Earth's mass, not its rotation. Option C is also wrong; temperature differences between seasons are due to Earth's tilt and its orbit around the Sun, not its rotation. Lastly, option D misrepresents the concept; the movement of continents is influenced by tectonic activity, not the rotation of Earth.
The rotation of Earth around its axis creates the day and night cycle, as different parts of the planet face the Sun and then move into its shadow. This explains why we experience daytime and nighttime in a 24-hour period. Option A is incorrect; gravity is primarily caused by Earth's mass, not its rotation. Option C is also wrong; temperature differences between seasons are due to Earth's tilt and its orbit around the Sun, not its rotation. Lastly, option D misrepresents the concept; the movement of continents is influenced by tectonic activity, not the rotation of Earth.
Which of the following is always true of a chemical change?
- A. Color, shape, or texture is altered.
- B. Mass is increased.
- C. A new substance is formed.
- D. Gas or vapor is generated.
Correct Answer & Rationale
Correct Answer: C
A chemical change always results in the formation of a new substance, which is a fundamental characteristic distinguishing it from physical changes. Option A is incorrect because while color, shape, or texture may change, these alterations do not confirm a chemical change unless a new substance is produced. Option B is misleading; mass is conserved in chemical reactions, so it does not necessarily increase. Option D, while often true (as gases can be produced), is not universally applicable; some reactions do not produce gas. Hence, the formation of a new substance is the definitive indicator of a chemical change.
A chemical change always results in the formation of a new substance, which is a fundamental characteristic distinguishing it from physical changes. Option A is incorrect because while color, shape, or texture may change, these alterations do not confirm a chemical change unless a new substance is produced. Option B is misleading; mass is conserved in chemical reactions, so it does not necessarily increase. Option D, while often true (as gases can be produced), is not universally applicable; some reactions do not produce gas. Hence, the formation of a new substance is the definitive indicator of a chemical change.
Which THREE of the following processes depend directly on energy from the Sun?
- A. Seafloor spreading
- B. The water cycle
- C. Photosynthesis
- D. Atmospheric circulation
Correct Answer & Rationale
Correct Answer: B,C,D
Energy from the Sun drives several essential processes on Earth. **The water cycle (B)** relies on solar energy to evaporate water from oceans and lakes, facilitating condensation and precipitation. **Photosynthesis (C)** is directly powered by sunlight, as plants convert solar energy into chemical energy, producing oxygen and glucose. **Atmospheric circulation (D)** is influenced by solar heating, which creates temperature gradients that drive wind patterns and weather systems. In contrast, **seafloor spreading (A)** is a geological process driven by tectonic activity and heat from the Earth's interior, not solar energy.
Energy from the Sun drives several essential processes on Earth. **The water cycle (B)** relies on solar energy to evaporate water from oceans and lakes, facilitating condensation and precipitation. **Photosynthesis (C)** is directly powered by sunlight, as plants convert solar energy into chemical energy, producing oxygen and glucose. **Atmospheric circulation (D)** is influenced by solar heating, which creates temperature gradients that drive wind patterns and weather systems. In contrast, **seafloor spreading (A)** is a geological process driven by tectonic activity and heat from the Earth's interior, not solar energy.